TAIPEI (Taiwan News) — The Ministry of National Defense detected 11 Chinese military aircraft and seven naval vessels around Taiwan between 6 a.m. on Saturday and Sunday.

Six of the aircraft reportedly entered the country’s southwestern air defense identification zone, or ADIZ, according to the ministry. In response, Taiwan sent aircraft and naval ships and deployed coastal-based missile systems to monitor PLA activity.

So far this month, Taiwan has tracked Chinese military aircraft 118 times and ships 63 times. Since September 2020, China has increased its use of gray zone tactics by incrementally increasing the number of military aircraft and naval vessels operating around Taiwan.

Gray zone tactics are defined as “an effort or series of efforts beyond steady-state deterrence and assurance that attempts to achieve one’s security objectives without resort to direct and sizable use of force.”